1. Field of the Invention
The present invention relates to a printing apparatus capable of reprinting print data, which has already been printed once, in accordance with a reprint instruction, and method of controlling the printing apparatus.
2. Description of the Related Art
After printing has been performed based upon print data received from a data processing apparatus such as a host computer, a user may wish to request that one more copy of the same data be printed. There is a reprinting technique (for example, see Japanese Patent Laid-Open No. 2001-75748) in which, in response to this request, print data is printed in accordance with a reprint instruction, which is issued by operating an operation panel on the printing apparatus, without resending the print data from the host computer.
With ordinary print processing, a printing apparatus stores a print job, which has been received from a host computer, in a secondary storage device possessed by the printing apparatus and, following the end of print processing, deletes the print job stored in the secondary storage device. On the other hand, with a printing apparatus capable of reprinting, the print job stored in the secondary storage device is not deleted but is left in the storage device even after print processing ends. As a result, by entering a reprint instruction from an operation panel on the printing apparatus, the user can reprint an image, which has already been printed once, without the print data being received from the host computer again.
With the conventional reprinting technique described above, an unspecified number of users can execute reprint by operating the operation panel on the printing apparatus. That is, it is possible for anyone to reprint another person's document without the permission of this person. This represents an extreme lack of confidentiality. As an example of a technique for solving this problem, Japanese Patent Laid-Open No. 2007-179140 proposes deleting a print job, which has been stored in a storage device of an image forming apparatus, if prescribed conditions are satisfied. For instance, in one example of a proposal, if a prescribed period of time elapses after a print job has been stored in the storage device, then the print job is deleted.
However, in a case where a print job is deleted upon elapse of a prescribed period of time, as with the technique proposed in Japanese Patent Laid-Open No. 2007-179140, a user who wishes to print the print job is inconvenienced if the prescribed period of time has been set to be too short. On the other hand, although convenience is enhanced if the prescribed period of time is set to be long, a problem which arises is sacrificed confidentiality with regard to a print-job document that has been stored in the printing apparatus.